Ederson left the field on a stretcher after eight minutes of treatment but was later cleared of serious injury. He was taken to the medical centre at the Etihad campus to check for fractures to his cheek, but appeared later by the City substitutes' bench.
The day opened with Manchester City thrashing Liverpool at the Etihad with Leroy Sane and Gabriel Jesus each scoring twice, and it ended with Manchester United drawing to end their flawless start to the season.
"I just have no faith with Jurgen Klopp in charge", he lamented.
"I know Lovren wasn't 100 per cent the manager said before the game".
Brother Phil disagreed, however, tweeting: "Red card for me - good decision Jon Moss".
Sergio Aguero had already put City into the lead when Mane was dismissed in the 37th minute for catching Ederson with a high boot in a nasty collision.
"I think he's massively important", Carragher told Sky Sports following Mane's goal against Crystal Palace. We can not play a game up and down. "Obviously we deserved to win".
United arrived without having conceded a goal in their three games but errors by Ivorian Eric Bailly and Phil Jones allowed Eric Maxim Choupo-Moting to pounce and score on both occasions.
Mané shares top spot at the top of the Premier League goalscoring charts with Manchester United striker Romelu Lukaku.
"We spoke at half-time and said: don't let them run".
TEAMS: Manchester City: Ederson, Danilo, Stones, Otamendi, Fernandinho, Walker, De Bruyne, David Silva, Mendy, Aguero, Gabriel Jesus. "We had to change something but they quietened us down very quickly".
"You can defend not perfectly and still win 5-0".
ROBERTO FIRMINO (replaced by Solanke, 67): Made a lot of the running up front but was never really able to have much influence in the final third. City can come late and then they pass between the lines.
Jose Mourinho's side drew level at the bet365 Stadium as Henrikh Mkhitaryan's corner in first half stoppage-time was headed goalwards by Paul Pogba before deflecting into the net off Marcus Rashford.